利用AOTF的可调谐光纤激光器的特性研究

Study on Characteristics of Tunable Fiber Laser Employing AOTF

提出了一种新型的可调谐光纤激光器 ,其谐振腔是由声光可调谐波长滤波器 (AOTF)和掺铒光纤构成的Fabry Perot腔。该激光器具有调谐方便 ,调谐速度快和调谐范围大的优点。在忽略激发态吸收和放大的自发辐射情况下 ,对该激光器的线宽和调谐特性以及阈值抽运功率和斜率效率进行了理论计算。在中心工作波长 15 5 0nm处 ,得到输出峰值的半极大值线宽 (FWHM)约为 0 2 6nm ,并且在 15 5 0nm附近 ,声波频率每改变 1MHz所调谐的峰值波长间隔约为 8 95nm。理论上 ,调谐范围只受掺铒光纤增益和滤波器带宽的限制。计算结果表明 ,该激光器的阈值抽运功率和斜率效率分别为 0 795mW和 15 15 %。

A new-style tunable fiber laser in which an acoustooptic tunable filter (AOTF) and an erbium-doped fiber are combined to form a Fabry-Perot resonator is presented and theoretically investigated in this article. It has wide tunable range and can be conveniently and rapidly tuned by changing the acoustic frequency. Under neglecting excited-state absorption (ESA) and amplification of spontaneous emission (ASE) the linewidth tunable characteristic, pump threshold and slope efficiency of the laser have been calculated. At the center wavelength of 1550 nm, an output peak with a FWHM of 0.26 nm is obtained; the tuned peak gap is about 8.95 nm when the acoustic frequency is changed per 1 MHz. Theoretically, the tunable range is confined only by erbium-doped fiber gain and filter bandwidth. The calculational results indicate the pump threshold and slope efficiency of this laser are 0.795 mW and 15.15%, respectively.